Were there knights in the 16th and 17th century?

Yes and no. There were knights, just as there are today (Sir Paul Macartney and Sir Elton John for example), but they no longer had a real military function. Heavily armoured men on horseback were not as effective once cannon and small arms had been invented. They therefore tended to be mere honorifics. Shakespeare makes fun of this with his characters Sir Toby and Sir Andrew in Twelfth Night.